This door in the old residential area of Guadalajara hides several communist motifs.

This singular Mexican structure is considered a masterpiece of the Tapatía architectural school.

A Red Cross memorial museum at the site of the Niš concentration camp that operated for four eventful years during World War II.

A pair of connected skyscrapers form this symbolic gateway.

Nikola Tesla's ashes are held in a golden sphere, surrounded by his works.

The oldest active church in Pennsylvania is also the second oldest Swedish Church in the United States.

This beloved marketplace mascot poops money and grants good luck.

The sounds of the world's largest fully functioning pipe organ dazzle shoppers at a Philadelphia Macy's.

This elaborate towering structure was once famed for its revolutionary height.

The first American department store, and home to the largest operating musical instrument in the world.

Tour the dark and beloved poet's former cobwebbed basement, which may have inspired "The Black Cat."

A second generation sun-powered marvel lights up the night.

The blinking light atop the iconic landmark has been sending secret messages for decades.

An historic and oft-filmed spot for musclebound iron pumpers on the Pacific coast.

First LEED-certified gas station in the United States.

In a city filled with Frank Gehry buildings, one stands out as one of the architect's weirder works.

The final resting place of a space program monolith.

A faux European lane smack dab in downtown L.A.

Historic funicular railway, believed to be the shortest railroad in the world.

World-famous, Pink's still manages to keep its prized cult fetish status.

Scores of vintage street lamps shine along L.A.’s Miracle Mile.

America's most famous piece of self-built architecture.

The world's first museum of its kind is packed with nostalgic relics of the past.

A beautiful example of 18th-century engineering still standing tall.